2001 XJ, The power windows work well but when the driver's side window reaches the top or bottom the motor will not stop and makes a stripping sound, is there a stop or a limit switch? What could be the problem?

Do a search for "Window Regulator" on this site and look for the multiple write-ups on the subject. It sounds like the Regulator motor is bad and will need replaced. I've not heard of any repairs for the motor itself, just a self repair for the gears and track after they fail. Good luck!!!

Here's the thing, the regulator is not hesitating or lacking any power while opening or closing the window. In fact it continues to work against the resistance of the window frame if I let it activated. That's why I thought that maybe there was some sort of limiter which tells the motor when to stop when it reaches the top, or not work when activated if it allready is at the top. Anyhow, thank's for all of your info and opinions! If somebody else knows any other reason for my window problem please let me know it will also be appreciated.